View source for CheckMate 743 Trial

{{#seo:
|title=CheckMate 743 Trial: The Study That Changed Mesothelioma Treatment
|description=The CheckMate 743 trial proved immunotherapy extends mesothelioma survival to 18.1 months—the first treatment breakthrough in 16 years. Learn about eligibility and results.
|keywords=CheckMate 743, mesothelioma immunotherapy, nivolumab ipilimumab, mesothelioma clinical trial, FDA approval 2020, Dr. Paul Baas, mesothelioma treatment
|image=checkmate-743-trial-results.jpg
|author=Danziger & De Llano Legal Team
|published_time=2026-01-28
}}
{| class="infobox" style="width:280px; float:right; margin:0 0 1em 1em; border:2px solid #1a5276; border-radius:8px; overflow:hidden;"
|-
! colspan="2" style="background:#1a5276; color:white; padding:12px; font-size:1.1em; text-align:center;" | CheckMate 743 Trial
|-
| colspan="2" style="padding:10px; text-align:center; font-style:italic;" | Landmark [[Mesothelioma]] Immunotherapy Study
|-
| style="padding:10px; font-weight:bold; width:40%; border-bottom:1px solid #dee2e6;" | Trial Type
| style="padding:10px; border-bottom:1px solid #dee2e6;" | Phase 3, Randomized
|-
| style="padding:10px; font-weight:bold; border-bottom:1px solid #dee2e6;" | Patients
| style="padding:10px; border-bottom:1px solid #dee2e6;" | 605
|-
| style="padding:10px; font-weight:bold; border-bottom:1px solid #dee2e6;" | Countries
| style="padding:10px; border-bottom:1px solid #dee2e6;" | 21
|-
| style="padding:10px; font-weight:bold; border-bottom:1px solid #dee2e6;" | Lead Investigator
| style="padding:10px; border-bottom:1px solid #dee2e6;" | [[Dr_Paul_Baas|Dr. Paul Baas]]
|-
| style="padding:10px; font-weight:bold; border-bottom:1px solid #dee2e6;" | FDA Approval
| style="padding:10px; border-bottom:1px solid #dee2e6;" | October 2, 2020
|-
| style="padding:10px; font-weight:bold; " | Survival Benefit
| style="padding:10px;" | 18.1 vs 14.1 months
|-
| colspan="2" style="background:#1a5276; padding:10px; text-align:center;" | [https://dandell.com/contact-us/ <span style="color:white; font-weight:bold;">Free Case Review →</span>]
|}

== Executive Summary ==

The CheckMate 743 trial represents the most significant breakthrough in mesothelioma treatment since the approval of chemotherapy in 2004.<ref>[https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-nivolumab-and-ipilimumab-unresectable-malignant-pleural-mesothelioma FDA Approves Nivolumab and Ipilimumab for Mesothelioma], U.S. Food and Drug Administration</ref> This phase 3 randomized study, led by [[Dr_Paul_Baas|Dr. Paul Baas]] at the Netherlands Cancer Institute, enrolled 605 patients across 21 countries and demonstrated that first-line treatment with nivolumab plus ipilimumab (immunotherapy) significantly improved survival compared to standard chemotherapy.<ref>[https://clinicaltrials.gov/study/NCT02899299 CheckMate 743 Trial Registration], ClinicalTrials.gov</ref> Patients receiving immunotherapy achieved median overall survival of 18.1 months versus 14.1 months with chemotherapy—a 26% reduction in death risk (hazard ratio 0.74).<ref>[https://dandell.com/malignant-mesothelioma/ Malignant Mesothelioma Lawyers], Danziger & De Llano</ref> These results led directly to FDA approval on October 2, 2020, establishing dual immunotherapy as the new global standard of care for unresectable malignant [[Pleural Mesothelioma|pleural mesothelioma]].<ref>[https://mesothelioma.net/immunotherapy/ Immunotherapy for Mesothelioma], Mesothelioma.net</ref>

== Key Facts ==

{| class="wikitable" style="width:100%; margin:1em 0; border-collapse:collapse;"
|-
! style="background:#1a5276; color:white; padding:12px; text-align:left;" | Key Facts: CheckMate 743 Trial Results
|-
| style="padding:15px; " |
* '''Enrollment:''' 605 patients with previously untreated unresectable malignant pleural mesothelioma
* '''Countries:''' 21 nations participated in the global trial
* '''Randomization:''' 1:1 ratio to immunotherapy or chemotherapy
* '''Treatment Arm:''' Nivolumab (Opdivo) 3 mg/kg every 2 weeks + Ipilimumab (Yervoy) 1 mg/kg every 6 weeks
* '''Control Arm:''' Pemetrexed + cisplatin or carboplatin (standard chemotherapy)
* '''Median Survival (Immunotherapy):''' 18.1 months
* '''Median Survival (Chemotherapy):''' 14.1 months
* '''Hazard Ratio:''' 0.74 (26% reduction in death risk)
* '''Two-Year Survival:''' 41% immunotherapy vs 27% chemotherapy
* '''Non-Epithelioid Benefit:''' Survival doubled from 8.8 to 18.1 months
* '''FDA Approval Date:''' October 2, 2020
* '''Publication:''' The Lancet, January 2021
|}

== What Was the CheckMate 743 Trial and Why Did It Matter? ==

CheckMate 743 was an open-label, phase 3, randomized clinical trial designed to determine whether dual immune checkpoint inhibitor therapy could improve survival in patients with malignant pleural mesothelioma compared to standard platinum-based chemotherapy.<ref>[https://www.cancer.gov/about-cancer/treatment/clinical-trials Clinical Trials Information], National Cancer Institute</ref>

Before this trial, mesothelioma patients had essentially one first-line treatment option: pemetrexed combined with cisplatin or carboplatin. This chemotherapy regimen had been the standard of care since FDA approval in 2004—a span of 16 years without any significant treatment advances.<ref>[https://dandell.com/mesothelioma-diagnosis/ Mesothelioma Diagnosis Guide], Danziger & De Llano</ref>

{| style="width:100%; border:1px solid #007bff; border-left:5px solid #007bff; border-radius:4px; margin:1em 0;"
|-
| style="padding:15px; " | '''Info: Why "CheckMate"?''' Bristol-Myers Squibb's immunotherapy clinical trial program uses the "CheckMate" naming convention. The number 743 simply identifies this specific trial within their research portfolio. The name has become synonymous with the mesothelioma immunotherapy breakthrough.
|}

The trial was led by [[Dr_Paul_Baas|Dr. Paul Baas]], a Dutch thoracic oncologist at the Netherlands Cancer Institute who had spent decades working to improve mesothelioma treatment. His international team included researchers from the United States, France, Australia, the United Kingdom, and other countries.<ref>[https://mesothelioma.net/treatment-for-mesothelioma/ Mesothelioma Treatment], Mesothelioma.net</ref>

{| style="width:95%; margin:1em auto; border-left:4px solid #1a5276; border-radius:4px;"
|-
| style="padding:15px 20px 10px; font-style:italic; font-size:1.05em; line-height:1.5;" | "For 16 years, we could only offer our newly diagnosed clients one treatment option. CheckMate 743 changed everything. Now when we meet with mesothelioma patients, we can discuss immunotherapy—a treatment proven to extend survival and give families precious additional time together."
|-
| style="padding:5px 25px 20px; text-align:right;" | '''— Paul Danziger,''' Founding Partner, Danziger & De Llano
|}

== How Was the CheckMate 743 Trial Designed? ==

The trial's rigorous design ensured that its results would be scientifically valid and applicable to real-world mesothelioma patients.<ref>[https://www.cancer.gov/about-cancer/treatment/clinical-trials/what-are-trials What Are Clinical Trials?], National Cancer Institute</ref>

=== Patient Eligibility ===

To enroll in CheckMate 743, patients had to meet specific criteria:<ref>[https://dandell.com/mesothelioma-compensation/ Mesothelioma Compensation], Danziger & De Llano</ref>

* Confirmed diagnosis of unresectable malignant pleural mesothelioma (any histologic subtype)
* No prior systemic therapy for mesothelioma
* Adequate organ function
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

=== Treatment Arms ===

{| class="wikitable" style="width:100%; margin:1em 0;"
|-
! style="background:#1a5276; color:white; padding:10px;" | Arm
! style="background:#1a5276; color:white; padding:10px;" | Treatment
! style="background:#1a5276; color:white; padding:10px;" | Schedule
|-
| style="padding:10px;" | '''Immunotherapy'''
| style="padding:10px;" | Nivolumab 3 mg/kg IV + Ipilimumab 1 mg/kg IV
| style="padding:10px;" | Nivolumab every 2 weeks; Ipilimumab every 6 weeks; continued until progression or toxicity
|-
| style="padding:10px;" | '''Chemotherapy'''
| style="padding:10px;" | Pemetrexed 500 mg/m2 IV + Cisplatin 75 mg/m2 (or Carboplatin AUC 5) IV
| style="padding:10px;" | Every 3 weeks for up to 6 cycles
|}

The trial randomized patients 1:1 to either treatment arm. The primary endpoint was overall survival—the gold standard for cancer clinical trials.<ref>[https://mesothelioma.net/clinical-trials-for-mesothelioma-treatment-what-to-expect/ Clinical Trials for Mesothelioma Treatment], Mesothelioma.net</ref>

== What Were the Key Results of CheckMate 743? ==

The results, published in The Lancet in January 2021, demonstrated clear superiority for the immunotherapy combination across multiple measures.<ref>[https://pubmed.ncbi.nlm.nih.gov/33485464/ Baas P et al. Lancet. 2021], PubMed</ref>

=== Primary Endpoint: Overall Survival ===

{| class="wikitable" style="width:100%; margin:1em 0;"
|-
! style="background:#1a5276; color:white; padding:10px;" | Outcome
! style="background:#1a5276; color:white; padding:10px;" | Immunotherapy
! style="background:#1a5276; color:white; padding:10px;" | Chemotherapy
! style="background:#1a5276; color:white; padding:10px;" | Difference
|-
| style="padding:10px;" | Median Overall Survival
| style="padding:10px;" | '''18.1 months'''
| style="padding:10px;" | 14.1 months
| style="padding:10px;" | +4 months
|-
| style="padding:10px;" | Two-Year Survival Rate
| style="padding:10px;" | '''41%'''
| style="padding:10px;" | 27%
| style="padding:10px;" | +14%
|-
| style="padding:10px;" | Hazard Ratio for Death
| colspan="3" style="padding:10px; text-align:center;" | '''0.74''' (95% CI: 0.61-0.89; p=0.002)
|}

The hazard ratio of 0.74 means that patients receiving immunotherapy had a 26% lower risk of death at any given time point compared to those receiving chemotherapy.<ref>[https://dandell.com/malignant-mesothelioma/ Malignant Mesothelioma Lawyers], Danziger & De Llano</ref>

=== Results by Histologic Subtype ===

Perhaps the most dramatic finding was the differential benefit based on mesothelioma cell type:<ref>[https://seer.cancer.gov/statfacts/html/meso.html Cancer Stat Facts: Mesothelioma], NCI SEER Program</ref>

{| style="width:100%; border:1px solid #28a745; border-left:5px solid #28a745; border-radius:4px; margin:1em 0;"
|-
| style="padding:15px; " | '''Breakthrough for Non-Epithelioid Patients:''' Patients with non-epithelioid mesothelioma (sarcomatoid and biphasic subtypes) historically had the worst prognosis. In CheckMate 743, these patients saw their median survival more than '''double'''—from 8.8 months with chemotherapy to 18.1 months with immunotherapy.
|}

{| class="wikitable" style="width:100%; margin:1em 0;"
|-
! style="background:#1a5276; color:white; padding:10px;" | Subtype
! style="background:#1a5276; color:white; padding:10px;" | Immunotherapy Survival
! style="background:#1a5276; color:white; padding:10px;" | Chemotherapy Survival
! style="background:#1a5276; color:white; padding:10px;" | Improvement
|-
| style="padding:10px;" | Epithelioid
| style="padding:10px;" | 18.7 months
| style="padding:10px;" | 16.5 months
| style="padding:10px;" | +2.2 months
|-
| style="padding:10px;" | '''Non-Epithelioid'''
| style="padding:10px;" | '''18.1 months'''
| style="padding:10px;" | '''8.8 months'''
| style="padding:10px;" | '''+9.3 months (doubled)'''
|}

This finding was particularly significant because non-epithelioid mesothelioma had long been considered nearly untreatable.<ref>[https://mesothelioma.net/sarcomatoid-mesothelioma/ Sarcomatoid Mesothelioma], Mesothelioma.net</ref>

== How Did CheckMate 743 Lead to FDA Approval? ==

Based on the strength of the trial results, the FDA approved the combination of nivolumab plus ipilimumab on October 2, 2020—even before the full results were published in The Lancet.<ref>[https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-nivolumab-and-ipilimumab-unresectable-malignant-pleural-mesothelioma FDA Approves Nivolumab and Ipilimumab], U.S. Food and Drug Administration</ref>

{| class="wikitable" style="width:100%; margin:1em 0;"
|-
! style="background:#1a5276; color:white; padding:10px;" | Milestone
! style="background:#1a5276; color:white; padding:10px;" | Date
! style="background:#1a5276; color:white; padding:10px;" | Significance
|-
| style="padding:10px;" | Trial Enrollment Completed
| style="padding:10px;" | 2018
| style="padding:10px;" | 605 patients enrolled
|-
| style="padding:10px;" | Interim Analysis Positive
| style="padding:10px;" | 2020
| style="padding:10px;" | Primary endpoint met
|-
| style="padding:10px;" | FDA Approval
| style="padding:10px;" | October 2, 2020
| style="padding:10px;" | First new mesothelioma drug in 16 years
|-
| style="padding:10px;" | The Lancet Publication
| style="padding:10px;" | January 2021
| style="padding:10px;" | Full results published
|-
| style="padding:10px;" | EMA Approval
| style="padding:10px;" | 2021
| style="padding:10px;" | European approval followed
|}

This approval established dual immune checkpoint inhibitor therapy as the new global standard of care for previously untreated unresectable malignant pleural mesothelioma.<ref>[https://dandell.com/mesothelioma-lawyers/ Top-Rated Mesothelioma Lawyers], Danziger & De Llano</ref>

{| style="width:95%; margin:1em auto; border-left:4px solid #1a5276; border-radius:4px;"
|-
| style="padding:15px 20px 10px; font-style:italic; font-size:1.05em; line-height:1.5;" | "The FDA approval based on CheckMate 743 was a watershed moment. For the first time in 16 years, mesothelioma patients had a new treatment option—one that offered significantly better outcomes, especially for those with non-epithelioid disease who previously had so few options."
|-
| style="padding:5px 25px 20px; text-align:right;" | '''— Rod De Llano,''' Founding Partner, Danziger & De Llano
|}

== How Does the Immunotherapy Combination Work? ==

Nivolumab and ipilimumab work by different but complementary mechanisms to help the immune system recognize and attack mesothelioma cells.<ref>[https://www.cancer.gov/about-cancer/treatment/types/immunotherapy Immunotherapy to Treat Cancer], National Cancer Institute</ref>

=== Nivolumab (Opdivo) ===

Nivolumab is a PD-1 inhibitor. Cancer cells often express a protein called PD-L1 that binds to PD-1 on immune cells, essentially telling the immune system to "stand down" and not attack. Nivolumab blocks this interaction, allowing immune cells to recognize and destroy cancer cells.<ref>[https://www.cancer.gov/publications/dictionaries/cancer-terms/def/pd-1-inhibitor PD-1 Inhibitor Definition], NCI Dictionary of Cancer Terms</ref>

=== Ipilimumab (Yervoy) ===

Ipilimumab is a CTLA-4 inhibitor. CTLA-4 is another "checkpoint" that normally limits immune cell activation. By blocking CTLA-4, ipilimumab enhances the immune system's ability to mount a sustained attack against cancer cells.<ref>[https://www.cancer.gov/publications/dictionaries/cancer-terms/def/ctla-4 CTLA-4 Definition], NCI Dictionary of Cancer Terms</ref>

=== Why Dual Checkpoint Inhibition? ===

The combination of these two drugs produces better results than either alone because they target different points in the immune response:<ref>[https://mesothelioma.net/mesothelioma-emerging-treatments-research/ New Mesothelioma Treatments and Research], Mesothelioma.net</ref>

* '''Ipilimumab''' activates immune cells at an early stage, priming them to attack
* '''Nivolumab''' removes the "brakes" that cancer cells use to hide from activated immune cells

This dual mechanism creates a more comprehensive anti-tumor immune response.<ref>[https://dandell.com/mesothelioma-diagnosis/ Mesothelioma Diagnosis Guide], Danziger & De Llano</ref>

== Who Is Eligible for Immunotherapy Based on CheckMate 743? ==

The FDA approved nivolumab plus ipilimumab for adult patients with unresectable malignant pleural mesothelioma who have not received prior systemic therapy.<ref>[https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/125554s090lbl.pdf Opdivo (Nivolumab) Prescribing Information], FDA</ref>

'''Appropriate Candidates:'''
* Diagnosis of malignant pleural mesothelioma (any histologic subtype)
* Disease that cannot be surgically removed (unresectable)
* No prior chemotherapy or [[Immunotherapy for Mesothelioma|immunotherapy for mesothelioma]]
* Adequate organ function
* Ability to tolerate treatment side effects

{| style="width:100%; border:1px solid #ffc107; border-left:5px solid #ffc107; border-radius:4px; margin:1em 0;"
|-
| style="padding:15px; " | '''Important Consideration:''' While immunotherapy is now a first-line option, the choice between immunotherapy and chemotherapy should be made in consultation with an experienced oncologist. Some patients may benefit more from chemotherapy, particularly those who need rapid tumor response.
|}

== What Side Effects Were Observed in CheckMate 743? ==

Like all cancer treatments, the immunotherapy combination can cause side effects. In CheckMate 743, the most common treatment-related adverse events included:<ref>[https://dandell.com/mesothelioma-compensation/ Mesothelioma Compensation], Danziger & De Llano</ref>

{| class="wikitable" style="width:100%; margin:1em 0;"
|-
! style="background:#1a5276; color:white; padding:10px;" | Side Effect
! style="background:#1a5276; color:white; padding:10px;" | Immunotherapy
! style="background:#1a5276; color:white; padding:10px;" | Chemotherapy
|-
| style="padding:10px;" | Diarrhea
| style="padding:10px;" | 26%
| style="padding:10px;" | 35%
|-
| style="padding:10px;" | Fatigue
| style="padding:10px;" | 24%
| style="padding:10px;" | 25%
|-
| style="padding:10px;" | Pruritus (itching)
| style="padding:10px;" | 21%
| style="padding:10px;" | 4%
|-
| style="padding:10px;" | Rash
| style="padding:10px;" | 21%
| style="padding:10px;" | 5%
|-
| style="padding:10px;" | Nausea
| style="padding:10px;" | 17%
| style="padding:10px;" | 51%
|}

Importantly, serious side effects (grade 3-4) occurred at similar rates between the two treatment arms. Immunotherapy side effects are generally immune-related and can usually be managed with appropriate medical care.<ref>[https://mesothelioma.net/treatment-for-mesothelioma/ Mesothelioma Treatment], Mesothelioma.net</ref>

== What Does CheckMate 743 Mean for Mesothelioma Patients Today? ==

The approval of nivolumab plus ipilimumab based on CheckMate 743 has fundamentally changed the treatment landscape for mesothelioma patients.<ref>[https://www.cancer.gov/types/mesothelioma/patient/mesothelioma-treatment-pdq Mesothelioma Treatment (PDQ)], National Cancer Institute</ref>

'''For Newly Diagnosed Patients:'''
* A proven first-line treatment option beyond chemotherapy
* Particularly important for non-epithelioid subtypes
* Available at major [[Mesothelioma_Treatment_Centers|mesothelioma treatment centers]]
* Covered by most insurance plans

'''For the Field of Mesothelioma Research:'''
* Validated immunotherapy as effective against mesothelioma
* Opened doors for additional immunotherapy research
* Led to trials of immunotherapy in earlier disease stages
* Sparked investigation of immunotherapy combinations with surgery

{| style="width:95%; margin:1em auto; border-left:4px solid #1a5276; border-radius:4px;"
|-
| style="padding:15px 20px 10px; font-style:italic; font-size:1.05em; line-height:1.5;" | "CheckMate 743 gave our clients something they desperately needed: hope. When we tell newly diagnosed patients that there are now two proven treatment options—and that immunotherapy can more than double survival for some—we're sharing the results of this landmark trial. It changes the conversation from despair to possibility."
|-
| style="padding:5px 25px 20px; text-align:right;" | '''— David Foster,''' Client Advocate, Danziger & De Llano
|}

== Get Help Today ==

If you or a loved one has been diagnosed with mesothelioma, accessing the latest treatments—including the immunotherapy validated by CheckMate 743—is critical. You may also be entitled to significant compensation from the companies responsible for your [[Asbestos Exposure|asbestos exposure]].<ref>[https://dandell.com/whats-your-case-worth/ What's Your Mesothelioma Case Worth?], Danziger & De Llano</ref>

The experienced mesothelioma attorneys at Danziger & De Llano have helped thousands of families navigate both the medical and legal challenges of this diagnosis.<ref>[https://www.mesotheliomalawyercenter.org/entity/mesothelioma/ Mesothelioma: Diagnosis, Treatment & Legal Help], Mesothelioma Lawyer Center</ref>

For veterans with mesothelioma, the VA provides specialized benefits and healthcare services.<ref>[https://www.va.gov/disability/eligibility/hazardous-materials-exposure/asbestos/ VA Asbestos Exposure], U.S. Department of Veterans Affairs</ref>

Call (866) 222-9990 or [https://dandell.com/contact-us/ request a free case review online].

== See Also ==

* [[Dr_Paul_Baas|Dr. Paul Baas]] (Lead Investigator)
* [[History_of_Mesothelioma_Research|History of Mesothelioma Research]]
* [[Clinical_Trials|Clinical Trials]]
* [[Treatment_Options|Treatment Options]]
* [[Immunotherapy for Mesothelioma|Immunotherapy]]
* [[Mesothelioma_Treatment_Centers|Mesothelioma Treatment Centers]]

== References ==

<references />

[[Category:Mesothelioma Research]]
[[Category:Clinical Trials]]
[[Category:Mesothelioma]]
[[Category:Treatment History]]